Best Tank Mates for Sterbai Cory: Compatible Fish and Species to Avoid

The best sterbai cory tank mates are peaceful, small-mouthed fish that like the same warm, soft water, such as discus, rams, Apistogramma, cardinal tetras, pencilfish and small gouramis. Skip anything big enough to swallow a 2.5-inch catfish, anything that nips, and coldwater species like goldfish. Below you'll find the reasoning, a quick-reference chart, sample stocking plans for common US tank sizes, and the mistakes that trip up most keepers.

Why Sterbai Corys Are a Special Case

Corydoras sterbai is a peaceful, shoaling bottom scavenger from the upper Rio Guaporé on the Brazil–Bolivia border. Adults reach about 2.5 inches (6–7 cm). A few reports mention 3–4 inches (7.5–10 cm), but that's rare. You can recognize them by their dark body covered in white spots and their orange-tinted pectoral fin spines and ventral fins.

What sets sterbai apart from most corys is heat tolerance. Many cory species prefer cooler water, but sterbai is comfortable at the temperatures discus, German blue rams and apistos need. That makes it one of the few catfish that can go into a true warm-water South American tank.

Water and tank basics

Parameter	Recommendation
Temperature	73–82°F (23–28°C); 75–80°F (24–27°C) is ideal
Discus-tank ceiling	Up to about 84°F (29°C) with strong aeration
pH	Roughly 6.0–7.6
Hardness	Soft to moderately hard, about 2–15 dGH
Minimum tank	20–25 gallons (75–95 L); a 29–30 gallon long is better for a group plus mates
Group size	6 minimum, 8 or more is better
Substrate	Fine, smooth sand; rounded fine gravel is acceptable

A few notes on where advice differs:

• Temperature. Generic cory care sheets often say 70–78°F (21–26°C). Sterbai handles more. Run 75–80°F in a normal community tank. Going up to about 84°F (29°C) is fine for discus setups as long as oxygen levels stay high.
• Tank size. You'll see 10 gallons (38 L) quoted for corys in general. For sterbai, plan on at least 20 gallons, and choose a long footprint over a tall one. These fish use floor space, not height.
• Group size. Some sources say 4–6. Keep at least 6. Smaller groups tend to hide and act skittish. Other cory species don't really fill out the group, although mixed corys will often school loosely together.

Sharp or dirty gravel wears down the barbels, which are the whisker-like sensors corys use to find food.

The Three-Part Rule for Choosing Tank Mates

Sterbai corys are harmless to every fish in the tank. The risk runs the other way: they're vulnerable to anything that can swallow them, pick at them, or beat them to food on the bottom. Check any candidate against these three filters, in this order:

1. Temperature overlap. Choose species whose comfortable range sits inside roughly 75–82°F (24–28°C). If a fish needs water below 72°F (22°C), or above 84°F, it's a poor match no matter how peaceful it is.
2. Temperament and mouth size. The fish should be peaceful and too small to eat a 2.5-inch cory. Nippers are out, even if they're small.
3. Where it lives in the tank. Favor fish that use the middle and upper water column. Keep the bottom layer light, for example a group of corys, a few kuhli loaches and one bristlenose, so they don't all fight over the same sinking food.

Best Tank Mates for Sterbai Cory

Warm-water favorites

These species share sterbai's taste for warm, soft water, which makes them the best fits:

• Discus. Probably the classic pairing. Sterbai is one of the best cory choices for a discus tank.
• German blue rams and Bolivian rams. Dwarf cichlids that stay small and mostly ignore corys.
• Apistogramma. They may chase a cory away from a cave during spawning, but they can't hurt an adult.
• Cardinal tetras, rummy-nose tetras and ember tetras. Schooling mid-water fish that like the same conditions. You can browse small community tetras to find a school.
• Pencilfish and hatchetfish. Quiet fish for the upper water column, with tiny mouths.
• Dwarf, honey and pearl gouramis. Calm, slow fish that stay near the top.
• Harlequin and other rasboras. Hardy, peaceful schoolers.
• Bettas. Calm individuals usually do well (more on this below).

Other good fits (with a few caveats)

• Most small tetras. Neon tetras work, though they prefer the cooler end of the range.
• Otocinclus. Small, peaceful algae grazers.
• Bristlenose plecos. Fine as long as the tank is big enough that the pleco doesn't hog the floor.
• Kuhli loaches. Gentle bottom dwellers. Just count them toward your bottom-layer stocking.
• Other peaceful corys. See the FAQ on mixing species.
• Platies, guppies and mollies. They're peaceful, but livebearers prefer harder, more alkaline water than sterbai. This pairing is a compromise, not an ideal match. If you do it, aim for the middle of both fish's ranges instead of pushing to either extreme.

Snails and shrimp

• Nerite, mystery and ramshorn snails are completely safe.
• Adult cherry shrimp and amano shrimp are generally safe. Corys might pick off a tiny shrimplet now and then, but most of the time they don't bother.

The "it depends" group

• Barbs. Avoid tiger barbs and other nippy barbs. Cherry barbs are calm and work well.
• Angelfish. Medium angels with adult corys usually get along. Very large angels with small or juvenile corys are the risky combination, because a big angel may try to eat a small fish.
• Cichlids. A blanket "no cichlids" rule is too broad. Dwarf South American cichlids like rams and apistos are excellent. Large or territorial cichlids are not.

Tank Mates to Avoid

Species or group	Why to avoid
Oscars, Jack Dempseys, convicts, most mid-to-large cichlids	Will eat or bully corys
Larger African cichlids	Aggressive, and prefer hard alkaline water
Arowanas	Predatory, and far too large
Redtail catfish; pictus catfish in small tanks	Can swallow corys or outcompete them
Very large adult angelfish (rare cases)	May eat small corys
Tiger barbs and other nippy barbs	Nip fins and barbels
Serpae tetras	Fin nippers
Some red-tail sharks	Territorial on the bottom
Freshwater pufferfish	Nip fins and barbels
Goldfish	Need cooler water, grow large and produce heavy waste
White cloud minnows, hillstream loaches	Need cooler water
Crayfish and large crabs	Claws, and they steal food
Big plecos or clown loaches in a cramped tank	Outcompete corys for bottom food

Sample Stocking Plans for US Tank Sizes

These are starting points for a planted, well-filtered tank with regular water changes.

• 20 gallon long (75 L): 6 sterbai, a school of 8–10 ember tetras or pencilfish, and a few nerite snails. Keep the upper levels lightly stocked.
• 29 gallon (110 L): 8 sterbai, 12 cardinal tetras and a pair of German blue or Bolivian rams.
• 40 gallon breeder (150 L): 8–10 sterbai, 15 rummy-nose tetras, a pair of Apistogramma or a honey gourami, plus a few otocinclus.
• 55 gallon (208 L): 10 sterbai, a large school of cardinals or harlequin rasboras, a pair of rams, a small group of hatchetfish and one bristlenose pleco.
• 55–75 gallon discus plan (208–284 L): A small group of discus, 8–10 sterbai, and a school of cardinal tetras. Run it at 82–84°F (28–29°C) with strong surface agitation or an air stone for oxygen, and use a wide tank so the corys have plenty of floor.

Feeding: Make Sure the Corys Actually Eat

Sterbai are bottom feeders. Fast mid-water fish like tetras and rasboras can grab most of the food before it hits the floor, so a cory can slowly starve in a well-fed tank. To avoid that:

• Drop sinking pellets or wafers right after the lights go off, when the corys get active and the tetras settle down.
• Target-feed frozen bloodworms or brine shrimp with a turkey baster or feeding tube placed near the sand.
• Feed the mid-water fish first at the surface, then add the sinking food while they're busy.
• Don't count on leftovers. Corys need their own food.

Handling and Transport

Sterbai have stiff pectoral and dorsal spines that can lock into place and snag in net mesh. The spines also carry a mild toxin. Move them in a cup or small container instead of a net when you can. Never bag corys with other fish in a small amount of water, because a stressed cory can release that toxin into the bag.

Sterbai vs. Corydoras haraldschultzi

These two look alike and are sometimes mixed up. The quickest tell is the head: sterbai has a dark head with light spots, while C. haraldschultzi has the reverse pattern, a light head with dark spots. Sterbai also has the orange-tinted pectoral spines described above.

Common Mistakes and Troubleshooting

• Buying 2–3 as a cleanup crew. Small groups stay stressed and hidden. Start with 6.
• Assuming they live on leftovers. Give them dedicated sinking food.
• Eroded or red barbels. This usually means sharp gravel or high nitrate. Switch to fine sand and increase water changes.
• Temperature mismatches. Keeping them with coldwater fish, or running 86°F (30°C) or higher without extra aeration, puts them under stress.
• Adding them to an uncycled tank. Corys are sensitive to ammonia. They're also sensitive to medications like copper and some ich treatments. Use half doses or treat with care.
• Misreading surface dashes. An occasional dart to the surface is normal air gulping. Frequent, frantic darting points to low oxygen or poor water quality, so test your water and add aeration.
• Skipping quarantine. Ich and stress losses right after shipping are common. Quarantine new arrivals before they join the main tank.

Frequently Asked Questions

Can sterbai corys live with discus?

Yes. Sterbai is one of the best cory choices for a discus tank because it handles warmth better than most species. Keep the tank around 82–84°F (28–29°C) with strong oxygenation and a large footprint so the corys have room to forage.

Can a sterbai cory live with a betta?

Usually, yes, in a tank of 20 gallons (75 L) or more with plenty of plants. Watch the betta's temperament. A territorial individual that patrols the bottom may harass the corys and need to be moved.

Will sterbai corys eat shrimp?

They won't bother adult cherry or amano shrimp. They may occasionally eat a tiny baby shrimp they come across.

Can I mix sterbai with other corys?

Yes, but keep 6 or more of each species so each one behaves naturally. Match temperatures too. Panda and peppered corys prefer cooler water than sterbai, so they aren't ideal for a warm tank.

How many sterbai corys fit in a 20 gallon tank?

About 6, with light stocking in the upper levels. A 20 long (75 L) is much better than a 20 high because the corys need floor space.

Do sterbai corys eat algae?

Not really. They scavenge for food on the bottom and don't graze algae. If you want algae control, add otocinclus or nerite snails.

Build Your Sterbai Community

Once you've settled on your tank mates, start with a proper group of at least six and add companions gradually after quarantine. You can browse sterbai and other catfish in FishyHub's Plecos, Corys & Bottom Dwellers category.